8024395: Improve fix for line break calculations

Reviewed-by: alexp, alexsch

2 files changed, 65 insertions, 31 deletions

diff --git a/src/share/classes/javax/swing/text/FlowView.java b/src/share/classes/javax/swing/text/FlowView.java
index e04b2fe91..8cd647ce9 100644
--- a/src/share/classes/javax/swing/text/FlowView.java
+++ b/src/share/classes/javax/swing/text/FlowView.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2008, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -796,6 +796,22 @@ public abstract class FlowView extends BoxView {
             v.setParent(parent);
         }
 
+        /** {@inheritDoc} */
+        @Override
+        protected void forwardUpdate(DocumentEvent.ElementChange ec,
+                                          DocumentEvent e, Shape a, ViewFactory f) {
+            calculateUpdateIndexes(e);
+            // Send update event to all views followed by the changed place.
+            lastUpdateIndex = Math.max((getViewCount() - 1), 0);
+            for (int i = firstUpdateIndex; i <= lastUpdateIndex; i++) {
+                View v = getView(i);
+                if (v != null) {
+                    Shape childAlloc = getChildAllocation(i, a);
+                    forwardUpdateToView(v, e, childAlloc, f);
+                }
+            }
+        }
+
         // The following methods don't do anything useful, they
         // simply keep the class from being abstract.
 
diff --git a/src/share/classes/javax/swing/text/View.java b/src/share/classes/javax/swing/text/View.java
index c2e1e023d..be3a0e433 100644
--- a/src/share/classes/javax/swing/text/View.java
+++ b/src/share/classes/javax/swing/text/View.java
@@ -1137,32 +1137,9 @@ public abstract class View implements SwingConstants {
      */
     protected void forwardUpdate(DocumentEvent.ElementChange ec,
                                       DocumentEvent e, Shape a, ViewFactory f) {
-        Element elem = getElement();
-        int pos = e.getOffset();
-        int index0 = getViewIndex(pos, Position.Bias.Forward);
-        if (index0 == -1 && e.getType() == DocumentEvent.EventType.REMOVE &&
-            pos >= getEndOffset()) {
-            // Event beyond our offsets. We may have represented this, that is
-            // the remove may have removed one of our child Elements that
-            // represented this, so, we should foward to last element.
-            index0 = getViewCount() - 1;
-        }
-        int index1 = index0;
-        View v = (index0 >= 0) ? getView(index0) : null;
-        if (v != null) {
-            if ((v.getStartOffset() == pos) && (pos > 0)) {
-                // If v is at a boundary, forward the event to the previous
-                // view too.
-                index0 = Math.max(index0 - 1, 0);
-            }
-        }
-        if (e.getType() != DocumentEvent.EventType.REMOVE) {
-            index1 = getViewIndex(pos + e.getLength(), Position.Bias.Forward);
-            if (index1 < 0) {
-                index1 = getViewCount() - 1;
-            }
-        }
-        int hole0 = index1 + 1;
+        calculateUpdateIndexes(e);
+
+        int hole0 = lastUpdateIndex + 1;
         int hole1 = hole0;
         Element[] addedElems = (ec != null) ? ec.getChildrenAdded() : null;
         if ((addedElems != null) && (addedElems.length > 0)) {
@@ -1173,11 +1150,9 @@ public abstract class View implements SwingConstants {
         // forward to any view not in the forwarding hole
         // formed by added elements (i.e. they will be updated
         // by initialization.
-        index0 = Math.max(index0, 0);
-        index1 = Math.max((getViewCount() - 1), 0);
-        for (int i = index0; i <= index1; i++) {
+        for (int i = firstUpdateIndex; i <= lastUpdateIndex; i++) {
             if (! ((i >= hole0) && (i <= hole1))) {
-                v = getView(i);
+                View v = getView(i);
                 if (v != null) {
                     Shape childAlloc = getChildAllocation(i, a);
                     forwardUpdateToView(v, e, childAlloc, f);
@@ -1187,6 +1162,39 @@ public abstract class View implements SwingConstants {
     }
 
     /**
+     * Calculates the first and the last indexes of the child views
+     * that need to be notified of the change to the model.
+     * @param e the change information from the associated document
+     */
+    void calculateUpdateIndexes(DocumentEvent e) {
+        int pos = e.getOffset();
+        firstUpdateIndex = getViewIndex(pos, Position.Bias.Forward);
+        if (firstUpdateIndex == -1 && e.getType() == DocumentEvent.EventType.REMOVE &&
+            pos >= getEndOffset()) {
+            // Event beyond our offsets. We may have represented this, that is
+            // the remove may have removed one of our child Elements that
+            // represented this, so, we should forward to last element.
+            firstUpdateIndex = getViewCount() - 1;
+        }
+        lastUpdateIndex = firstUpdateIndex;
+        View v = (firstUpdateIndex >= 0) ? getView(firstUpdateIndex) : null;
+        if (v != null) {
+            if ((v.getStartOffset() == pos) && (pos > 0)) {
+                // If v is at a boundary, forward the event to the previous
+                // view too.
+                firstUpdateIndex = Math.max(firstUpdateIndex - 1, 0);
+            }
+        }
+        if (e.getType() != DocumentEvent.EventType.REMOVE) {
+            lastUpdateIndex = getViewIndex(pos + e.getLength(), Position.Bias.Forward);
+            if (lastUpdateIndex < 0) {
+                lastUpdateIndex = getViewCount() - 1;
+            }
+        }
+        firstUpdateIndex = Math.max(firstUpdateIndex, 0);
+    }
+
+    /**
      * Forwards the <code>DocumentEvent</code> to the give child view.  This
      * simply messages the view with a call to <code>insertUpdate</code>,
      * <code>removeUpdate</code>, or <code>changedUpdate</code> depending
@@ -1345,4 +1353,14 @@ public abstract class View implements SwingConstants {
     private View parent;
     private Element elem;
 
+    /**
+     * The index of the first child view to be notified.
+     */
+    int firstUpdateIndex;
+
+    /**
+     * The index of the last child view to be notified.
+     */
+    int lastUpdateIndex;
+
 };